Optimized Field-Weakening Operation of PMSM Modulated Model Predictive Control Using Predictive Current Error Margin

Considering the intrinsic defects of finite control set MPC (FCS-MPC), e.g., torque ripple and various harmonic frequencies, the modulated model predictive control (M2PC) has been regarded as a promising approach to achieve high performance of permanent magnet synchronous motor (PMSM) drives. However, the M2PC still faces non-minimum tracking error and unreasonable trajectory settings when rated-speed operation extends to the field-weakening (FW) region since the intervention of multiple constraints of voltage and current has to be taken into account. To address this problem, an M2PC-based scheme is proposed to realize the field-weakening operation with minimum tracking error and reasonable trajectory setting. Specifically, the equal proportion algorithm is replaced by an algebraical way for minimum tracking error in the over-modulation region; the predictive current error margin is used to preset the current trajectory in FW operation. Besides, the pre-triggering method is applied to reduce the control delay and eliminate the cumulative error, which improves the tolerance of parameter perturbation. Comparison results conducted on a Zynq7020-based PMSM setup validate the superiority of the proposed method regarding the capability of high-speed operation and high-dynamic performance.